1. Field of the Invention
The present invention relates to an optical communication module and a control method for the optical communication module.
2. Description of the Related Art
In order to realize a compact, low-power, and low-cost design for an optical communication module, a technology for making an optical module, which is mounted in the optical communication module, compact, low-power, and low-cost has been developed. For example, an optical module having an external modulation device and operating at a wavelength of 1550 nm is employed in an optical communication module for an intermediate or long transmission distance of 40 km or more. Especially, for the form factor of a pluggable module requested to be compact, an optical module in which an electro-absorption optical modulation device that utilizes electro-absorption is mounted as the external modulation device is adopted.
Some electro-absorption optical modulation devices include, as described in, for example, patent document 1 (JP 2000-91695A), a temperature control circuit, which keeps the temperature of the electro-absorption optical device constant, because the optical absorption characteristic thereof changes with an environmental change such as a change in temperature.